Catalog > Internet of Things (IOT) Related Products > More Platforms 4 Channel Relay Shield 4 Channel Relay Shield CMU 4 CHANNEL RELAY SHIELD 4 CHANNEL RELAY SHIELD COMPATIBLE WITH ARDUINO. 5VDC 3A 120VAC/24VDC Discontinued Specifications, Prices & Availability may change without notice. Images are for illustration purposes only. E&OE Overview 100% brand new and high quality Relay Shield (ie 5V Quad Relay Module) is a small current signal control power equipment commonly used electronic module, enabling high-power single-chip control devices are widely used in SCM system to make smart home project; and can be directly plugged into the Arduino compatible the use of various types of motherboards, eliminating the patch cable troubles. Features Standard For Arduino Shield interfaces and shape Can continue to stack other For Arduino expansion boards 3 M3 screw positioning holes for easy installation High Drive (5V or 3.3V) normally open contact closure Onboard relay indicator (red) Special Note: When using the For Arduino UNO board connected to it, because UNO USB interface is extremely high, should avoid green terminals are shorted its shell. Relay Shield Interface: (the last picture show) Relay: sky- 5V DC relay , model HJR-4102-L-5V, which Relay1 behalf of the 1st relay , the other and so on. Power Interface : 5V DC power interface Indicator: four lights are red when the relay is driven high , the corresponding indicator will light up. Relay Terminals: Terminal high-power , high-current high voltage can be connected to the device . The 1st foot ( i.e. NOx) is a normally open pin , NCx pin is normally closed , COMx is common, i.e., when the relay is not driven , NOx and COMx open between two pins , NCx and COMx connection ; When the relay (x) control signal pin is high drive relays , NOx and COMx connection open between NCx and COMx.